In general, a light source unit for a projector includes a high-pressure discharge lamp and a concave reflection mirror. The concave reflection mirror includes a concave reflection surface and a tubular holding portion formed at the bottom side of the reflection surface. Japanese Unexamined Patent Application Publication No. 2006-172810 (JP2006-172810A) discloses a configuration in which a ceramic-made base member is disposed at the rear surface side of a holding portion of a concave reflection mirror and in which one end of a high-pressure discharge lamp is held by the base member.
In the conventional light source unit, the high-pressure discharge lamp includes a pair of external electrodes (external leads). One of the external electrodes positioned at the front surface side of the concave reflection mirror is connected to a power supply line through a through-hole formed in the concave reflection mirror. If an external force is applied to the power supply line, an unnecessary force is exerted on the high-pressure discharge lamp. This may pose a problem in that the high-pressure discharge lamp is tilted and the light emitting point is shifted away from a center axis of the concave reflection mirror.
In order to avoid this problem, it is necessary to fix a ring-shaped terminal to the through-hole of the concave reflection mirror by means of, e.g., a grommet member, and to fix the power supply line to the ring-shaped terminal by welding, fitting, caulking or the like. However, this step makes a manufacturing process complex.